Hybrid organic-inorganic nanoparticles: controlled incorporation of gold nanoparticles into virus-like particles and application in surface-enhanced Raman spectroscopy.

A capsid is the protein coat surrounding a virus' genome that ensures its protection and transport. The capsid of murine polyomavirus (muPy) consists of one major (VP1) and two minor (VP2/3) proteins, from which just VP1 is sufficient to form the capsid when expressed recombinantly (1). From a material engineering point of view, viral capsids are of interest because they present a paradigm for complex self-assembly on the nanometer scale. Understanding and controlling these assembly dynamics will allow the construction of nanoscale structures using a self-assembly process. The first step in this direction was the discovery that capsids of several viruses can be reversibly disassembled into their building blocks and reassembled using the same building blocks by simply changing the buffer conditions (2, 3). Such capsids already find applications as targeted in vivo delivery vectors for genes, proteins or small molecular drugs (4, 5), as optical probes for biomedical imaging and sensing purposes with unprecedented resolution and sensitivity and can potentially be used as templates for nanoelectronics (6, 7)

Balanced Connected Partitioning of Unweighted Grid Graphs

We consider a partitioning problem for grid graphs with special constraints: a (square) grid graph as well as a number of colors is given, a solution is a coloring approximatively assigning the same number of vertices to each color and such that the induced subgraph for each color is connected. In a "rooted" variant, a vertex to be included in the coloring for each color is specified as well. This problem has a concrete motivation in multimedia streaming applications. We show that the general problem is NP-complete. On the other hand, we define a reasonable easy subclass of grid graphs for which solutions always exist and can be computed by a greedy algorithm

On the Connection of Partial Order Logics and Partial Order Reduction Methods

. We examine the connection between "equivalence robust" subsets of propositional temporal logics (LTL and CTL*), for which partial order reduction methods can be applied in model checking, and partial order logics and equivalences. For the linear case we show how to naturally translate "equivalence robust" LTL properties into Thiagarajan's linear time temporal logic for traces (TrPTL), substantiating the claim that partial order logics have the right syntax for equivalence robust properties. For the branching case we define a parametrised dependency relation (D; V ) yielding an (D; V )-equivalence notion for trees that generalizes Mazurkiewicz's trace equivalence. Then, we show that under some condition (D;V )-equivalent trees are stuttering equivalent and therefore cannnot be distinguished by any CTL-X formulas. We prove that partial order reductions for CTL-X give (D; V )-equivalent trees. Our approach can be used as a semantic basis for branching time partial order logic..